JP5677212B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine having a rotor in which a permanent magnet is housed in each housing hole formed in the outer circumferential portion along the circumferential direction.

In the embedded magnet type electric motor, a leakage magnetic flux that short-circuits the magnetic flux of the permanent magnet in the rotor is generated through the magnetic path on the outer periphery of the rotor core, so that the output is reduced.
In order to improve the output of the embedded magnet type motor, in order to increase the magnetic resistance of the short circuit magnetic path on the outer periphery of the rotor core and reduce the amount of magnetic flux leakage, an opening is formed on the outer diameter side of the storage hole storing the permanent magnet. Is known (see, for example, Patent Document 1).

  In this embedded magnet type electric motor, in order to prevent the permanent magnet from falling off due to the centrifugal force when the rotor rotates, a stopper is inserted into the opening to hold the permanent magnet, and this stopper is made of a non-magnetic material. The magnetic resistance in the magnetic path generated in the outer periphery of the rotor core is increased to suppress the leakage magnetic flux of the permanent magnet, thereby improving the output of the embedded magnet type electric motor.

JP 2009-153299 A

  However, in the embedded magnet type electric motor having the above configuration, in order to increase the holding strength of the permanent magnet, it is necessary to insert a stopper into the opening. There were problems such as deterioration in diameter.

  An object of the present invention is to solve the above-mentioned problems, and it is possible to improve output by suppressing generation of leakage flux of a permanent magnet while ensuring magnet holding strength without increasing the number of parts. An object of the present invention is to obtain a rotating electrical machine capable of achieving the above.

A rotating electrical machine according to the present invention includes a stator, and a rotor rotatably provided inside the stator,
The rotor includes a rotor core on which electromagnetic steel plates are laminated, and permanent magnets housed in respective housing holes respectively formed along the circumferential direction on the outer peripheral portion of the rotor core. From the permanent magnet, the stator A main magnetic flux that flows in a gap between the rotor and the rotor, and a rotating electric machine that generates a leakage magnetic flux that flows in a short circuit from the N pole to the S pole in the rotor core,
The rotor core is provided with a coupling means for mechanically coupling the laminated electromagnetic steel sheets to the short circuit path of the leakage magnetic flux at the outer peripheral portion ,
The permanent magnet has a rectangular parallelepiped shape, and the permanent magnet is embedded in the receiving hole with the longitudinal direction oriented in the radial direction,
In the outer peripheral portion of the rotor core, an opening that communicates the gap and the accommodation hole is formed,
The opening and the coupling means are provided in a region sandwiched in a circumferential direction by an imaginary line in which a pair of opposed long sides of the permanent magnet extends in a radially outward direction .

  According to the rotating electrical machine of the present invention, since the rotor core is provided with the coupling means that mechanically couples the laminated electrical steel sheets in the short circuit path of the leakage magnetic flux at the outer peripheral portion, the magnetic means of the electrical steel sheet is provided by the coupling means. As the characteristics deteriorate, the magnetic resistance in the short-circuit path increases, and as a result, the generation of leakage flux of the permanent magnet is suppressed, so that the magnet holding strength is ensured without increasing the number of parts, and The output can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an interior magnet type electric motor according to Embodiment 1 of the present invention. 2A is a side view of the main part of the interior magnet type electric motor of FIG. 1, and FIG. 2B is a plan view of FIG. It is the schematic of the magnetic flux which generate | occur | produces in the permanent magnet of the interior magnet type electric motor of FIG. It is a plane sectional view which shows the rotor of the interior magnet type electric motor in Embodiment 2 of this invention. FIG. 5 is a partial perspective view of the rotor of FIG. 4. It is the schematic of the magnetic flux which generate | occur | produces in the permanent magnet of the interior magnet type electric motor of FIG. It is a top view which shows the modification of the rotor of FIG. It is a principal part perspective view which shows the rotor of the interior magnet type electric motor in Embodiment 3 of this invention. It is the schematic of the leakage magnetic flux which generate | occur | produces in the permanent magnet of the interior magnet type electric motor of FIG. It is a principal part perspective view which shows the rotor of the interior magnet type electric motor in Embodiment 4 of this invention. It is the schematic of the leakage magnetic flux which generate | occur | produces in the permanent magnet of the interior magnet type electric motor of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent members and parts will be described with the same reference numerals.

Embodiment 1 FIG.
1 is a cross-sectional view showing an embedded magnet type electric motor, which is a rotating electrical machine according to Embodiment 1 of the present invention, FIG. 2 (a) is a side view of the main part of the embedded magnet type electric motor of FIG. 1, and FIG. ) Is a plan view of FIG.
This embedded magnet type electric motor is an electric motor for an electric power steering apparatus, and includes a stator 1 and a rotor 2 rotatably provided inside the stator 1.
The stator 1 has an electromagnet 5 in which a coil 4 is wound around each tooth 3 formed at intervals in the circumferential direction.
The rotor 2 has a rectangular parallelepiped shape housed in a rotor core 6 in which electromagnetic steel plates 10 are laminated and the shaft passes through the shaft hole 9, and in each housing hole 7 formed in the outer peripheral portion of the rotor core 6 along the circumferential direction. Permanent magnet 8.
The permanent magnet 8 is embedded in the receiving hole 7 with its longitudinal direction oriented in the circumferential direction, and S and N poles are magnetized along a radial line with the center line of the shaft hole 9 as a base point. ing.
As shown in FIG. 3, the permanent magnet 8 generates a main magnetic flux A flowing in the gap between the stator 1 and the rotor 2 and a leakage magnetic flux B flowing short-circuited from the N pole to the S pole in the rotor core 6. .

The rotor core 6 is provided with a coupling means 12 that mechanically couples the laminated electromagnetic steel sheets 10 in the short circuit path of the leakage flux B on the outer peripheral portion.
The coupling means 12 is a fastening body composed of, for example, a bolt (not shown) penetrating the electromagnetic steel sheet 10 and a nut (not shown) screwed to the tip of the bolt.
The coupling means 12 includes a concave portion (not shown) formed in one of the adjacent electromagnetic steel plates 10 and a convex portion (not shown) formed in the other electromagnetic steel plate 10 and fitted into the concave portion. Z)).

In the interior magnet type motor according to this embodiment, since the coupling means 12 is provided in the short circuit path, the magnetic resistance of the short circuit path increases, and the flow of leakage magnetic flux in the short circuit path is suppressed.
That is, when the coupling means 12 is a fastening body, the bolt has a magnetic permeability smaller than that of the magnetic steel sheet 10, and an air gap having a small magnetic permeability is between the peripheral surface of the bolt and the peripheral surface of the bolt hole of the magnetic steel sheet 10. Further, a residual stress is generated by drilling the electromagnetic steel sheet 10, thereby deteriorating the magnetic characteristics, and the magnetic resistance of the portion of the coupling means 12 of the rotor core 6 is increased as compared with other portions of the rotor core 6. .
Further, when the coupling means 12 is a caulking body, the magnetic steel sheet 10 has a magnetic permeability compared to other parts of the electromagnetic steel sheet 10 that is not deformed because residual stress is generated in the compressive deformation part due to elastic stress or plastic deformation. The magnetic characteristics are deteriorated and the magnetic resistance is increased.

As described above, by providing the coupling means 12 that mechanically couples the laminated electromagnetic steel plates 10 to the short-circuit path of the leakage flux B, the magnetic resistance of the short-circuit path increases while ensuring the mechanical strength of the rotor core 6. To do.
Accordingly, since the flow of leakage flux B in the short-circuit path is suppressed, leakage flux B generated in the outer peripheral portion of the rotor core 6 is suppressed, the main flux A is relatively increased, and the gap between the stator 1 and the rotor 2 is increased. Since the flowing main magnetic flux A increases, the output torque of the embedded magnet type motor increases, and the embedded magnet type motor is reduced in size and weight.

  In addition, since this miniaturized and lightweight embedded magnet type motor is used in an electric power steering device, the electric power steering device is reduced in size, weight, and output, thereby reducing the fuel consumption of an automobile. be able to.

Embodiment 2. FIG.
4 is a plan sectional view showing a rotor 2A of an embedded magnet type electric motor according to Embodiment 2 of the present invention, FIG. 5 is a partial perspective view of the rotor 2A of FIG. 4, and FIG. 6 is an illustration of the embedded magnet type electric motor of FIG. It is the schematic of the magnetic flux which generate | occur | produces in the permanent magnet 8. This permanent magnet 8 is accommodated in the accommodating hole 7A with the longitudinal direction oriented in the radial direction, and S and N poles are magnetized along the circumferential direction. ing.
An opening 11 is formed in the outer peripheral portion of the rotor core 6A to communicate the gap between the stator 1 and the rotor 2A and the accommodating hole 7A. The opening 11 extends linearly along the axial direction.
The rotor core 6A is provided with a coupling means 12 that mechanically couples the laminated electromagnetic steel sheets 10 in the short circuit path of the leakage flux B on the outer peripheral portion.
Other configurations are the same as those of the interior magnet type electric motor of the first embodiment.

According to the embedded magnet type electric motor according to this embodiment, since the flow of leakage magnetic flux in the short-circuit path is suppressed by the coupling means 12, leakage magnetic flux generated in the outer peripheral portion of the rotor core 6A is suppressed, and relatively The main magnetic flux i increases.
Accordingly, since the main magnetic flux A flowing in the gap between the stator 1 and the rotor 2 increases, the output torque of the embedded magnet type motor increases.
In addition, since the opening 11 is formed in the short circuit path, the magnetic resistance of the short circuit path is further increased, and the main magnetic flux A flowing through the gap between the stator 1 and the rotor 2 is increased. And the output of the interior magnet type motor is further improved.

  As shown in FIG. 7, the permanent magnet 8 may be inclined with respect to the radial line R in order to ensure the retention of the permanent magnet 8 against the centrifugal force.

Embodiment 3 FIG.
FIG. 8 is a partial perspective view showing a rotor 2B of an embedded magnet type electric motor according to Embodiment 3 of the present invention, and FIG. 9 is a schematic diagram of leakage magnetic flux generated in the permanent magnet 8 of the embedded magnet type electric motor of FIG. The permanent magnet 8 is housed in the housing hole 7A with the longitudinal direction oriented in the radial direction. An opening 11A is formed in the outer peripheral portion of the rotor core 6B to communicate the gap between the stator 1 and the rotor 2A and the accommodation hole 7A.
The opening 11 </ b> A is formed in a staggered pattern along the stacking direction for each electromagnetic steel sheet 10.
The rotor core 6B is provided with a coupling means 12 that mechanically couples the laminated electromagnetic steel sheets 10 in the short circuit path of the leakage flux B on the outer peripheral portion. This leakage flux B flows by short-circuiting the layers of the laminated electromagnetic steel sheets 10.
Other configurations are the same as those of the interior magnet type electric motor of the first embodiment.

According to the embedded magnet type electric motor according to this embodiment, since the flow of leakage flux B in the short circuit path is suppressed by the coupling means 12, leakage flux B generated in the outer peripheral portion of the rotor core 6B is suppressed, and relatively The main magnetic flux i increases.
Accordingly, since the main magnetic flux A flowing in the gap between the stator 1 and the rotor 2B increases, the torque of the embedded magnet type electric motor increases and the output of the embedded magnet type electric motor improves.
Moreover, since the opening part 11A is formed in a staggered pattern along the stacking direction for each electromagnetic steel sheet 10, and the outer peripheral part of the rotor core 6B is partially overlapped with the adjacent electromagnetic steel sheets 10, it is permanent. The holding force against the centrifugal force of the magnet 8 increases.

Embodiment 4 FIG.
10 is a partial perspective view showing a rotor 2C of an embedded magnet type electric motor according to Embodiment 4 of the present invention, and FIG. 11 is a schematic diagram of leakage flux B generated in the permanent magnet 8 of the embedded magnet type electric motor of FIG. The permanent magnet 8 is housed in the housing hole 7A with the longitudinal direction oriented in the radial direction. An opening 11B is formed in the outer peripheral portion of the rotor core 6C to communicate the gap between the stator 1 and the rotor 2C and the accommodation hole 7A.
The opening 11B is formed in a staggered pattern along the stacking direction for each steel plate block of the plurality of electromagnetic steel plates 10.
The rotor core 6 </ b> C is provided with coupling means 12 that mechanically couples the laminated electrical steel sheets 10 in the short circuit path of the leakage flux B on the outer peripheral portion. This leakage flux B flows by short-circuiting the layers of the laminated electromagnetic steel sheets 10.
Other configurations are the same as those of the interior magnet type electric motor of the first embodiment.

According to the embedded magnet type electric motor according to this embodiment, since the flow of leakage flux B in the short circuit path is suppressed by the coupling means 12, leakage flux B generated in the outer peripheral portion of the rotor core 6B is suppressed, and relatively The main magnetic flux i increases.
Accordingly, since the main magnetic flux A flowing in the gap between the stator 1 and the rotor 2B increases, the output torque of the embedded magnet type motor increases.

Moreover, the opening part 11B is formed in a staggered pattern along the stacking direction for each steel plate block, and the outer peripheral part of the rotor core 6B is partially overlapped with adjacent steel plate blocks.
Accordingly, when the leakage magnetic flux B flowing in the stacking direction flows to the portion of the steel plate block opposed through the opening 11B, the steel plate blocks are concentrated on the overlapping portion of the steel plate blocks. Occurs and the magnetic resistance increases.
That is, compared with the embedded magnet type electric motor of the third embodiment in which the leakage flux B is short-circuited between adjacent laminations of the electromagnetic steel plates 10, the leakage flux B generated in the outer peripheral portion of the rotor 2 is suppressed, The main magnetic flux i is relatively increased.
From this, in the embedded magnet type electric motor of this embodiment, the leakage flux B is further suppressed as compared with the third embodiment in which there are many leakage fluxes B that flow by shorting the layers of the laminated electromagnetic steel sheets 10, A higher output torque can be obtained.

In addition, also in the embedded magnet type electric motor of the first embodiment, an opening that communicates the gap and the accommodation hole 7 is formed in the outer peripheral portion of the rotor core 6 to increase the magnetic resistance in the short-circuit path of the leakage flux, Further, the output torque may be improved.
Further, in each of the embedded magnet type electric motors of the second to fourth embodiments, the openings 11, 11A, 11B are formed on the outer periphery of the rotor cores 6A, 6B, 6C. May not be provided on the outer peripheral portion of the rotor core as in the interior magnet type electric motor of the first embodiment shown in FIG.
In this case, the permanent magnet 8 with respect to centrifugal force is reduced, although the magnetic resistance of the short circuit path is reduced and the output torque of the embedded magnet type motor is reduced as compared with each of the embedded magnet type motors of the second to fourth embodiments. There is an advantage that the holding force increases.
Further, in the embedded magnet type electric motors of the third and fourth embodiments, as shown in FIG. 7, the permanent magnet 8 is positioned with respect to the radial line R in order to ensure the retention of the permanent magnet 8 against the centrifugal force. You may arrange inclining.
In each of the above embodiments, an embedded magnet type electric motor for an electric power steering device has been described as a rotating electric machine. However, the present invention can be applied to an electric motor for other uses, and can also be applied to a generator. .

  1 stator, 2, 2A, 2B, 2C rotor, 3 teeth, 4 coils, 5 electromagnet, 6, 6A, 6B, 6C rotor core, 7, 7A receiving hole, 8 permanent magnet, 9 shaft hole, 10 electromagnetic steel plate, 11 , 11A, 11B Opening, 12 coupling means, b main magnetic flux, b leakage magnetic flux.

Claims (9)

A stator and a rotor rotatably provided inside the stator;
The rotor includes a rotor core on which electromagnetic steel plates are laminated, and permanent magnets housed in respective housing holes respectively formed along the circumferential direction on the outer peripheral portion of the rotor core. From the permanent magnet, the stator A main magnetic flux that flows in a gap between the rotor and the rotor, and a rotating electric machine that generates a leakage magnetic flux that flows in a short circuit from the N pole to the S pole in the rotor core
The rotor core is provided with a coupling means for mechanically coupling the laminated electromagnetic steel sheets to the short circuit path of the leakage magnetic flux at the outer peripheral portion ,
The permanent magnet has a rectangular parallelepiped shape, and the permanent magnet is embedded in the receiving hole with the longitudinal direction oriented in the radial direction,
In the outer peripheral portion of the rotor core, an opening that communicates the gap and the accommodation hole is formed,
The rotating electrical machine, wherein the opening and the coupling means are provided in a region sandwiched in the circumferential direction by an imaginary line in which a pair of opposed long sides of the permanent magnet extends in a radially outward direction . A stator and a rotor rotatably provided inside the stator;
The rotor includes a rotor core on which electromagnetic steel plates are laminated, and permanent magnets housed in respective housing holes respectively formed along the circumferential direction on the outer peripheral portion of the rotor core. From the permanent magnet, the stator A main magnetic flux that flows in a gap between the rotor and the rotor, and a rotating electric machine that generates a leakage magnetic flux that flows in a short circuit from the N pole to the S pole in the rotor core
The rotor core is provided with a coupling means for mechanically coupling the laminated electromagnetic steel sheets to the short circuit path of the leakage magnetic flux at the outer peripheral portion ,
In the outer peripheral portion of the rotor core, an opening that communicates the gap and the accommodation hole is formed,
The rotating electrical machine according to claim 1, wherein the opening is formed by stacking the magnetic steel sheets partially in a staggered manner along the stacking direction . A stator and a rotor rotatably provided inside the stator;
The rotor includes a rotor core on which electromagnetic steel plates are laminated, and permanent magnets housed in respective housing holes respectively formed along the circumferential direction on the outer peripheral portion of the rotor core. From the permanent magnet, the stator A main magnetic flux that flows in a gap between the rotor and the rotor, and a rotating electric machine that generates a leakage magnetic flux that flows in a short circuit from the N pole to the S pole in the rotor core,
The rotor core is provided with a coupling means for mechanically coupling the laminated electromagnetic steel sheets to the short circuit path of the leakage magnetic flux at the outer peripheral portion ,
In the outer peripheral portion of the rotor core, an opening that communicates the gap and the accommodation hole is formed,
The rotating electrical machine according to claim 1, wherein the opening is formed by stacking a plurality of laminated steel sheet blocks partially in a staggered manner along the stacking direction . 4. The rotating electrical machine according to claim 2 , wherein the permanent magnet has a rectangular parallelepiped shape, and the permanent magnet is embedded in the receiving hole with a longitudinal direction oriented in a circumferential direction. 4. The rotating electrical machine according to claim 2 , wherein the permanent magnet has a rectangular parallelepiped shape, and the permanent magnet is embedded in the receiving hole with a longitudinal direction oriented in a radial direction. 4. The rotating electrical machine according to claim 2 , wherein the permanent magnet has a rectangular parallelepiped shape, and the permanent magnet is disposed to be inclined with respect to a radial line that is based on a center line of the rotor. . The said coupling | bonding means is a fastening body comprised from the volt | bolt which penetrated the said electromagnetic steel plate, and the nut screwed by the edge part of this volt | bolt, The any one of Claims 1-6 characterized by the above-mentioned. Rotating electric machine. The coupling means is a caulking body composed of a recess formed in one of the adjacent electromagnetic steel sheets and a protrusion formed in the other electromagnetic steel sheet and fitted into the recess. The rotating electrical machine according to any one of claims 1 to 6 . The rotating electrical machine according to any one of claims 1 to 8 , wherein the rotating electrical machine is an electric motor for an electric power steering apparatus.

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